Expandable linkage with detachable, spring tension adjusting pivots



L UV I NP. G m mm am m N m .1 m m April 2, 1957 EXPANDABLE LINKAGE WITH DETACHABLE, SPRING Filed March 2, 1955 2 Sheets-Sheet l n O M m J 6717/ 011 J Cawalz BY ATTORNEYS.

Aprll 2, 1957 A. M. ANDERSON ET AL 2,787,117

EXPANDABLE LINKAGE WITH DETACHABLE, SPRING TENSION ADJUSTING pxvo'rs Filed March 2, 1955, 2 Sheets-Sheet 2 IN VEN TOR. fl/ van 1% fi z de rs 01? 671 52 012 .176 0 W011 ATTORNEYS- EXPANDABLE LINKAGE WITH DETACHABLE, SPRING TENSION ADJUSTING PIVOTS Alvan M. Anderson, Barrington, R. I., and Clifton J. Cowan, Glen Ridge, N. J.

Application March 2, 1955, Serial No. 491,606

2 Claims. (Cl. 59--79) This invention relates to an expandable linkage such as may be used for a bracelet.

The expansion linkage may be either of two types, that is, there may be a so-called three-point suspension or a two-point suspension. The three-point suspension usually is used for the wider mens bracelet and the two-point suspension frequently is used for the narrow womens bracelets. The present invention relates to both types.

Expansion linkage such as that which is the subject of this invention is utilized largely as a wrist watch attachment although it may also be used in conjunction with identification plates, lockets, or other articles of utility or adornment. Bracelets of this character in the past have had all of the working parts manufactured from metal, such for instance as brass, stainless steel, gold fill, or silver strips.

The linkages heretofore sometimes have been connected by means of separate eyelets to provide the basic extendable linkage which requires considerable assembly operations, and thus the assembly is an important cost factor. The linkage may also be approached from a diiferent standpoint in which one of the members, frequently called the male post or lower link of the series, has posts or eyelets of the same piece of material as the link, which are drawn in the form of extruded tubes from the fiat stock of the link by a series of drawing operations. These drawing operations are performed in combination tools of very complicated design which require that the tools be extremely accurate in order that uniform parts may be formed. In this case the tools are exceedingly expensive to construct and maintain due to frequent repairs, and many duplicates are required in order that a continuous flow of parts of any given design may be had. This latter construction reduces the assembly cost, but the tools which are required are a material cost factor.

In each case above recited in the past there has been required a decorative shell formed for a bottom cover, the shell covering up the open ends of the exposed tubes drawn from fiat stock or the loose eyelets or tubular rivets described above. These backs or shells which extend over the male post or lower link member also act as stops for one end of the activating coil springs which keep the series of parts in contracted position.

The metal back shells which are thus utilized contact the wrist of the wearer and are subject to considerable corrosive action from body acids, perspiration, and so forth, which tend to discolor the links and to erode them to a point Where they lose their decorative and useful value. In some cases stainless steel is used for this bottom shell, and it has been found that stainless steel causes an inflammation or irritation of the skin of some people. i

In a copending application Serial No. 406,730 by Alvan M. Anderson, one of the joint inventors of this application, there is shown and described a construction of expandable linkage in which the back shell above nited States Patent 2,787,? Patented Apr. 2, 1957 mentioned may be eliminated. A stop other than the back shell is formed for the coiled spring. By molding the links from non-metallic material, machine operations on the links are eliminated, different colored materials may be used, the links are lightened in weight, noise due to the pivoting of the parts is reduced, and a wide range of designs is permitted. Further, this application above referred to simplified the assembly of the top and bottom links although it did require a heading over of the posts to hold the links assembled.

One of the objects of this invention is to retain the advantages obtained in the prior application referred to and to further simplify the assembly of the non-metallic links by eliminating the necessity of heading the posts after the placing of the links into pivotal relation.

Another object of the invention is to provide for the assembly of the non-metallic links by snapping them together.

Another object of the invention is to provide a shaping of the posts of the male or post link and a shaping of the openings of the female or washer link so that the two links may be snapped together and retained in this assembled relation.

A further object of the invention is to provide heads on the posts with smaller or neck portions below these heads and forming either the posts or the openings which receive the posts with some resilience in their walls so that the heads may pass through the openings by a change in size of the walls of one of the parts, which will then return by its inherent resiliency to its normal position and retain the parts assembled.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a top plan view of the expandable linkage in contracted position;

Figure 2 is a top plan view of the male or post or lower link of the linkage;

Figure 3 is a sectional view taken along the zig-zag line 3-3 of Figure 2;

Figure 4 is a top plan view of the female, washer or upper link;

Figure 5 is a section on line 5-5 of Figure 4;

Figure 6 is a section on line 6-6 of Figure 4;

Figure 7 is a perspective view of the spring which is used in the assembly of the links;

Figure 8 is a top plan view of the links in expanded relation;

Figure 9 is a view similar to Figure 8 on a larger scale but showing the tops of the ornamental shells in section to expose the operating parts of the assembly;

Figure 10 is a central sectional view on line Iii-10 of Figure 9 with the shell in place;

Figure 11 is a sectional view on line 11-11 of Figure 9 with the spring omitted;

Figure 12 is a sectional view on line Ill-12 of Figure 9;

Figure 13 is a plan view of a fragmentall portion of a modified female or upper link;

Figure 14 is a top plan view of a two-point suspension linkage which may be formed in accordance with the invention;

Figure 15 is a sectional view of a female, washer or upper link for a twopoint suspension linkage taken on line 15-15 of Figure 14; and

Figure 16 is a sectional view of a male or post or lower link for a two-point suspension linkage taken on line 16-16 of Figure 14.

In proceeding with this invention, we mold from nonof the post 19.

metallic material the 'basic linkage which is to form the expandable linkage of this invention. This will consist of a lower male or post link which will be of solid construction with posts extending upwardly therefrom, one of which will be hollow to receive the spring. These posts will be headed and at least one will be hollow. We will also mold from non-metallic material, a 'female, washer or upper link with openings which will receive the posts of the lower links. Either the posts will be resilient or the walls of the openings in the upper link will be resilient so that these links may be snapped into engagement with each other over the heads of the posts. A spring may be dropped into one of the hollow posts and have one of its ends held within the post while the other end of the spring will engage a lug or some holding means on the upper link so as to move the links into contracted position. In the three-point suspension type of linkage, the spring will be located in a ,hollow center post. In the two-point suspension type of linkage, each ofthe posts will be hollow, and two springs will be utilized, one in each post, for moving the links to contracted position. In each case the lower or post link will have .its bottom surface so formed that it will be smooth and finished and no shell need be provided for covering the same. A shell, however, is contemplated for the upper link to cover the spring and working parts and to provide an ornamental upper surface. However, by snapping the links together and by the elimination of a bottom shell, the assembly operations are greatly ,reduced and a great saving is effected from the assembly standpoint and a linkage having the advantages above pointed out in the objects of the invention is accomplished. \Vith reference to the drawings, the lower, post, or male link is designated generally 15 and is shown by itself in Figures 2 and 3. It is molded into the desired shape there shown and comprises from some such material as nylon or a suitable resin a solid body 16 from which solid posts 17--17 at its opposite ends extend upwardly. Each of these end posts has heads 13 at its upper end. A tubular center post extends upwardly from the mid portion of the body and is also provided with a head 20. This post is split axially by four slots 21 which form the same resilient so that it may be contracted and will return to its normal position after the contracting pressure is released. This link may be molded in finished form as shown and described without need for providing any finished outer surface at 22, as this will be sufiiciently finished as it comes from the mold. The post may be molded with the link in which case the slots make it resilient or the post may be of metal and separate from the link and slotted, also making it resilient. If separate, it will be held to the link against turning.

The female, washer or upper 'link is designated generally 23 and shown by itself in Figures 4, 5., and 6. This link has a generally rectangular body 24 with a recess or opening 25 in its .center which has a counterbore 26 at its upper end for the reception of the head Recesses 27 are provided adjacent the opposite ends of the upper link 23 of a size to receive the post 17. In order that the walls of this recess 27 may be resilient, we have provided slots 28 extending from the recess 27 outwardly to the end of the link so that the walls of the recess may expand and the recess may be snapped over the heads 18 of the post 1'7. Upstanding lugs 29 are provided between the recesses 25 and 27 and are in pairs provided with overhanging portions as shown at 36 (see Figure 6) and beneath which one end of the spring may be positioned as will be hereinafter explained. Openings 31 extending from beneath the overhanging portions of these lugs are provided. Upstanding projections 32 are provided .in pairs along either side of the slots 28 for the purpose of engaging and limiting the movement of a covering shell in position. Notches at 33, 34, 35, and 36 are provided on each .end of this link for the reception of projections on the cover or shell bracelet.

which is assembled with this link. These are symmetrically arranged with reference to the center of the link so that either end of the cover or shell may be assembled without regard to the lugs which are used for holding it in position.

A spring 37 is coiled as at 38 and provided with a short tail 39 and a longer tail 40. This spring may be received in the bore of post 19.

A shell or ornamental cover 41 is of generally rectangular shape (Figure 1) and is arched on its top as at 42 (Figure 19) with downwardly extending side walls 43. This shell will rest upon the posts 32 so as to limit its movement in telescoping over the upper link 23. The side walls 43 will be of such extent that they will engage the upper edge of the link 23. Portions 44 will project downwardly in the recesses 33 (Figure 9), portions 45 project downwardly in the recess 34, portions 46 project downwardly in the recess 35, and portions 47 project downwardly in the recess 36, all of which portions will be folded beneath the upper link as shown at 48 in Fig we 12. This holds the shell assembled to the upper link when in this position.

In assembling the parts heretofore referred to, the upper and lower links will first be assembled by positioning the recess or opening 25 of the upper link over the head 29 of the post 19 of the lower link by contracting this post by reason of its slots 21 to permit of this assembly. After inward yielding, the .post will expand so that the head will fit into the larger portion of the bore 26 and stay assembled therewith. After sections of units consisting of a lower and an upper link are assembled in this fashion, the sections are then assembled with each other to the desired length, the ends being interconnected, by snapping the recess 27 which is resilient by reason of the slots 28 over each or" the heads 13 of the posts 17 so that the assembly will be substantially as shown in Figures 8 and v9. The spring 37 is then dropped into the bore of post 19 with its short leg 39 in one of the slots 21, which causes the spring to be anchored in the post link 15 while the other end is moved to a position beneath one of the lugs 29 as may be seen in Figure 9. This tends to move the two links which the spring engages to contracted position such as shown in Figure 1, the expanded linkage being shown in Figures 8 and 9. The shells 41 are then assembled by positioning them in place over each of the upper links and bending the tongues 48 of the shells beneath the upper links as shown in Figure 12. The shells will be of metal although the links will be of non-metallic plastic material, probably nylon or some of the moldable resin materials.

In some cases the shells may be cemented in place rather than bending the edges or tongues of the shells inwardly. In other cases the shells may be formed of non-metallic material and interengaging connections provided for snapping them in place as a convenient means of assembly.

In Figure 13 we have shown the end portion of an upper link designated 23 in which the opening 5'2 is located wholly inwardly of the end 53 of the link. The walls of this opening 5?. are made resilient by slots 54 extending radially outwardly from the opening. This alternative form may be used instead of the slot 23 as shown in Figure 4 and will enable a link so formed to be snapped over the solidhead 13 of: the solid stud 17.

In the above we have described a so-called three-point suspension type of expansion linkage, but in the twopoint suspension type of linkage as shown in Figures 14-16, the links are each provided with posts 66 adjacent their opposite ends, which posts are hollow and split as at 67 and headed as at 68 in the same construction as the center post 19 in the three-point suspension No center post, however, exists in the two-- point suspension. Each of the upper links 69 are provided with recesses 70 having an enlarged bore 71 for the reception of the head 62? which may be passed over the resilient posts 66 of the lower links. These posts being hollow will each receive the coil 33 of a spring 37 with the tail portion 39 in one of the slots of the post and the other end 40 of the spring beneath one of the lugs '72 of the link.

We claim:

1. An expandable linkage comprising a series of upper links and a series of lower links, a tubular post of resilient material on each of the links of one series extending through an opening in the links of the other series, said post having a head thereon larger than said opening and being axially slotted for contraction in diameter to a size to pass the head through said opening, and a coiled spring mounted by each post and having one end anchored in said slot and the other end engaging a link of the other series to swing the links pivotally connected about the post as a pivot.

2. An expandable linkage comprising a series of upper links and a series of lower links, a tubular post of resilient material on each of the links of one series extending through an opening in the links of the other series, said post having a head thereon larger than said opening and being provided with a plurality of axially extending slots for contraction in diameter to a size to pass the head through said opening, and a coiled spring mounted by each post and having one end anchored in a selected one of said slots and the other end engaging a link of the other series to swing the links pivotally connected about the post as a pivot, said spring being adjustable as to tension by changing the anchored end to a different slot.

References Cited in the file of this patent UNITED STATES PATENTS 2,376,633 Szeglin et al. a- May 22, 1945 2,433,766 Kubice Dec. 30, 1947 2,663,971 Ippolito Dec. 29, 1953 

